(54) BIOSENSOR
(75) Inventors: Shin Ikeda, Katano; Toshihiko Yoshioka; Shiro Nankai, both of Hirakata, all of (JP)
(73) Assignee: Matsushita Electric Industrial Co., Ltd., Osaka-fu (JP)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/379,128
(22) Filed: Aug. 20, 1999
(30) Foreign Application Priority Data
Aug. 26, 1998 (JP) 10-239853
(51) Int. C I. A61B 5/05
(52) U.S. CI 600/345; 600/347; 204/403
(58) Field of Search 600/345, 346,
600/347, 365, 395, 396, 397; 204/403
(56) References Cited
U.S. PATENT DOCUMENTS
4,224,125 * 9/1980 Nakamura et al 204/403
4,897,173 * 1/1990 Nankai et al 204/403
5,264,103 * 11/1993 Yoshioka et al 204/403
5,496,453 * 3/1996 Uenoyama et al 204/403
5,540,828 * 7/1996 Yacynych 204/418
5,575,895 * 11/1996 Ikeda et al 204/403
5,582,697 * 12/1996 Ikeda et al 204/403
5,695,947 * 12/1997 Guo et al 435/11
A highly reliable biosensor is provided which is reduced in influences of any interfering substance or preexisting oxygen in a sample solution. The biosensor comprises an electrode system including a working electrode, a counter electrode and a third electrode also usable as an interfering substance detecting electrode, a reagent layer containing at least an oxidoreductase and an electron mediator, and an electrically insulating base plate for supporting the electrode system and the reagent layer, wherein the third electrode is arranged at an opposing position to that of at least one of the working electrode and the counter electrode and the reagent layer is arranged at a predetermined position apart from the third electrode.
6 Claims, 3 Drawing Sheets
